Sagitar idling engine room leaks air.

Check the pipe joint for air leakage. You can apply it with soapy water. If the seal is good, check whether the hose is broken. The method is the same. If there is a breakpoint, replace the hose. If you want to save money, you can use some raw material tape to tie it yourself, which has little effect on vehicle power.

It seems that the problem is not the pipeline, so we have to find the throttle. This pipeline is mainly used to connect the intake manifold and the throttle vacuum economizer. The problem may be the diaphragm of the vacuum economizer, because this diaphragm is usually rubber or metal and may break. When the cylinder takes in air, the vacuum in the pipeline rises and the air pressure drops. Outside air is sucked into the intake manifold from the vacuum economizer at the upper end of the throttle through the gap. Just like we whistle, air flow makes a sound when it passes through a narrow space. This is my personal analysis for your reference.